Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Premises and equipment [Abstract]
Premises and equipment, gross	$ 63,612,000	$ 61,496,000
Accumulated depreciation and amortization	(35,956,000)	(33,512,000)
Balance at end of year	27,656,000	27,984,000
Depreciation and amortization	2,572,000	2,510,000	2,535,000
Depreciation and amortization on property under capital lease	461,000	167,000	50,000
Land [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	Indefinite
Premises and equipment, gross	3,326,000	3,354,000
Premises [Member]
Premises and equipment [Abstract]
Premises and equipment, gross	28,167,000	27,830,000
Property under capital lease	5,000,000	5,000,000
Premises [Member] | Minimum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	30 years
Premises [Member] | Maximum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	40 years
Furniture, Fixtures & Equipment [Member]
Premises and equipment [Abstract]
Premises and equipment, gross	28,250,000	26,479,000
Furniture, Fixtures & Equipment [Member] | Minimum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	3 years
Furniture, Fixtures & Equipment [Member] | Maximum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	7 years
Leasehold Improvements [Member]
Premises and equipment [Abstract]
Premises and equipment, gross	$ 3,869,000	$ 3,833,000
Leasehold Improvements [Member] | Minimum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	2 years
Leasehold Improvements [Member] | Maximum [Member]
Premises and equipment [Abstract]
Estimated Useful Lives	25 years